Field
Implementations described herein generally relate to processes for the fabrication of semiconductor devices in which a self-assembled monolayer is used to achieve selective area deposition.
Description of the Related Art
Reliably producing sub-half micron and smaller features is one of the key technology challenges for next generation very large scale integration (VLSI) and ultra large scale integration (ULSI) of semiconductor devices. However, as the limits of circuit technology are pushed, the shrinking dimensions of VLSI and ULSI technology have placed additional demands on processing capabilities.
As circuit densities increase for next generation devices, the widths of interconnects, such as vias, trenches, contacts, gate structures and other features, as well as the dielectric materials therebetween, decrease to 45 nm and 32 nm dimensions and beyond. In order to enable the fabrication of next generation devices and structures, three dimensional (3D) stacking of features in semiconductor chips is often utilized. In particular, fin field effect transistors (FinFETs) are often utilized to form three dimensional (3D) structures in semiconductor chips. By arranging transistors in three dimensions instead of conventional two dimensions, multiple transistors may be placed in the integrated circuits (ICs) very close to each other. As circuit densities and stacking increase, the ability to selectively deposit subsequent materials on previously deposited materials becomes increasingly desirable.
Self-assembled monolayers (SAMs) may be utilized as a masking material to improve subsequent material deposition selectivity. SAMs are generally surface chemistry dependent and can be formed preferentially on various materials. However, SAMs may exhibit pin holes or voids in as deposited layers which may not effectively prevent deposition of subsequent material layers. Another drawback of SAMs is that the time for deposition may be very long and not economically feasible in semiconductor manufacturing processes.
Thus, there is a need for improved methods for SAM formation.